A bed base structure

Abstract: A bed base structure has a portion which can be bent to a desired curvature. This is achieved using a bendable bed base portion which is comprised of parallel rigid strips (9) joined by flexible strips (10) are formed as bendable sheets connecting adjacent faces of adjacent rigid strips (7) in such a way as to form the inside curve of the bendable base portion. Guard elements are provided to cover both of the strips at the bendable portion of the bed base. The guard members have bodies with engagement parts and covers. The covers (14) are so shaped as to overlap one another in such a way that they remain overlapped in all relative positions of the rigid strips of the bed base so as to prevent entrapment of fingers or the like as the bed base is adjusted to change its curvature.

Description: The present invention relates to a bed base structure having at least a portion which can be bent to a desired curvature without causing any displeasing feeling of pressure to a patient lying on the bed. Many recent beds have been equipped with an adjustment mechanism for example to allow a patient or other user of the bed to adopt a semi-recumbent position, and various mechanisms are available. A typical prior art bed has two base portions simply pivotally connected to each other at one point. One of these, the so-called back-support portion (so-called because it is intended to support the back of the user) can be turned about the pivotal connection to the other portion so as to adopt different inclined positions. When the back-support portion is inclined, however, the joint between the back-support portion and the main, or hip-support portion operates as a pivot: therefore, when the back-support portion is inclined up to a certain angle, the space between this and the hip-support portion near the joint is narrowed, and unless the bent portion of the bed base actually fits that patient's body his waist, abdomen and legs are uncomfortably pressed by the underside by the mattress. Other known bed base structures have further adjustable parts such as an adjustable leg-support portion having means by which it can be curved to vary its inclination with respect to the hip-support portion. This, too, suffers from the same problems that, basically, the pivot is offset from the patient's own joints (knees, hips, etc) so that changes in inclination cannot always be achieved in comfort due to the changes in the available space between inclined parts of a mattress. An alternative bed structure is described in EP-A-0 220 708 which incorporates a bendable portion between the back-support and hip-support portions. The bendable portion is made up from a plurality of substantially rigid transverse strips with adjacent strips being pivotally interconnected via integral hinge formations and associated hinge rods. The object of the present invention is to provide an alternative bed base structure, which can be bent in a desirable curvature in such a way that the bent portion is gently curved so as to ease the feeling of pressure to any size patient. According to one aspect of the present invention there is provided a bed base structure for an adjustable bed, including a bendable portion comprising a plurality of interconnected, substantially rigid, transverse support strips, characterised in that the rigid support strips are interconnected by flexible connector strips fixed to, or formed integrally with, adjacent said support strips so as to extend therebetween and interconnect them, the connector strips being so formed as to be deformable to a v-shape in cross-section when compressed by relative movement of the adjacent rigid strips to allow the said bed portion to adopt a curved configuration. The upper faces of the rigid strips may also be formed to include a sheet thus completing the inside curve of the bed base. The flexible strips may also be, or be associated with, longitudinally expandable flexible sheets. An adjustable bed base structure may comprise three main portions, namely a back-support portion, a central or hip-support portion, and a leg-support portion. The bed base structure of the invention may have a bendable portion at a position between the back-support portion and the hip-support portion. Further, the bed base structure may have a bendable portion provided at a position between the hip-support portion and the leg-support portion, corresponding to the knees. The bed base structure of the present invention may further include guards which are provided longitudinally in the region of the bendable portion, at both ends of the rigid strips of the bendable portions. The guards may comprise bodies engaged in the ends of respective rigid strips and provided with end covers. The end covers are so arranged that they can follow the bending motion of the flexible strips and help to maintain the curved state of the bendable portions of the bed base. Adjacent end covers overlap each other at their ends such that they can be displaced in relation to one another and adjusted to changes in the relative spacing of the rigid strips as the adjustable portions of the bed base are raised and lowered. According to another aspect of the present invention there is provided a bed base structure for an adjustable bed, including a bendable portion comprising a plurality of interconnected substantially rigid, transverse support strips, characterised in that the rigid support strips are interconnected by flexible connector strips fixed to, or formed integrally with, opposing faces of adjacent said support strips so as to extend between and interconnect them, the connector strips being so shaped as to allow relative approach and separation of adjacent said rigid support strips to allow the said bed portion to adopt a curved configuration. According to a further aspect of the invention there is provided a bed base structure for an adjustable bed, including a bendable portion comprising a plurality of interconnected, transverse, substantially rigid support strips, characterised in that it further includes a guard structure provided longitudinally along the bendable portion of the bed base structure, the guard structure having a plurality of separate and adjacent guard units each having engagement means engageable with an end of a respective rigid support strip whereby the said guard units can move relative to each other on bending of the bendable bed base portion. Embodiments of the present invention will now be more particularly described, by way of non-limitative example, with reference to the accompanying drawings, in which Figure 1 is a side view showing a section of a bed having a bed base formed in accordance with the inventions; Figure 2 is a plan view of a part of a bendable portion of the bed base of Figure 1, showing the location of the guard members; Figure 3 is a schematic sectional view showing another example of a bed base structure of the invention; Figure 4 is a plan view showing an end configuration of another example of a bendable portion and guard members prior to assembly; Figure 5 is an exploded perspective view showing one example of the structure of a guard member which can be attached to a rigid strip of a bendable portion of a bed base structure such as that shown in any of Figures 2, 3 or 4; Figure 6 is a schematic plan view showing the connection of another example of a guard which can be attached to the bendable portion, shown in the positions adopted when the bed base is in its flat state; Figure 7 is a schematic plan view showing the configuration of the guard of Figure 6 when the bed base is expanded or bent; and Figure 8 is a schematic sectional view, on an enlarged scale, showing another example of a structure of the bendable portion having rigid strips and connecting flexible strips. Referring now to the drawings, a bed base structure of a bed 1 has three main portions, namely a back-support portion 24, a hip-support (or central) portion 25 and a leg-support portion 26. The present invention presents a bed base structure wherein a first bendable portion 8 is provided in the bed base structure at a position between the back-support portion 24 and the central portion 25, and a second bendable portion 8' is provided at a position between the central portion 25 and the leg-support portion 26 corresponding to the knees. Each said bendable portion 8, 8' comprises a plurality of parallel rigid strips 9 joined by flexible strips 10 located between the adjacent sides of the rigid strips. The flexible strips 10 are preferably longitudinally (that is along the length of the bed base structure) expandable flexible strips. The strips preferably comprise or have associated therewith bendable sheets connecting the respective adjacent rigid strips on the side which forms the inside curve of the bed base when lifted or lowered. Further, the flexible strips may be formed so as to be folded in a V-shape when the bed base is bent, forming a curve in the bed base as will be described in more detail below. The rigid strips 9 are preferably hollow and preferably made of synthetic resin, and the flexible strips 10 are preferably formed so as to be thinner at their central portions and at or adjacent the portions intended to be connected to the rigid strips 9. The connection 20 (see Figure 8) with the rigid strip and the central portion 21 of the flexible strip may also be made of a material softer (ie more resilient) than that of the rest of the sheet. The rigid strips 9 and the flexible strips may be manufactured or formed as a single integrated unit, or formed separately and then connected subsequently. The bendable sheets constituting or associated with the flexible strips 10 can also be configured so as to be V-shaped and flexible. The flexible strip can be connected to either the upper edge (as shown in Figure 8) or the lower edge of the rigid strips of the bendable portion of the bed base so as to be on the inside of the curve formed when the bendable portion of the bed base structure is bent to a curve. For example, between the back-support portion 24 and the central portion 25, the bendable portion 8 forms a curve the inside face of which is the upper face when the bed base structure is lifted to an elevated position as shown in Figure 1. In this case the flexible strips are located close to the upper edges of adjacent rigid strips as shown in Figure 8. The bendable sheets comprising the flexible strips can be compressed into a V-shape as the curve is formed, and would be gradually elongated at the bottom surface of the bendable bottom component to gradually widen the spaces between the respectively adjacent rigid strips on the outside of the curve. As a result, the bendable portion of the bed base structure forms a smooth and gentle curve on the side in contact with the patient. The rigid strips provide the bed base support and either the flexible strips, the bendable sheets or the combination, provide the bendable dynamics of the bottom component. As a result, the bendable portion of the bed base forms a smooth and gentle curve. The bed base structure can also be provided with guards running longitudinally of the bed base which cover the side edges of the bed at least at the bendable portions. The guards comprise engagement members 13 engaged with the ends of respective rigid strips 9 and end covers. The end covers 14 interrelate with each other so that they can follow the bending motion of the flexible strips and the guards help to maintain the bent state of the curved portion of the bed base. The respective adjacent end covers 14 are designed to be displaceable with respect to one another but remain overlapped with respect to one another at their ends. The engagement members 13 themselves may be constructed of a main body 15 and a cover 16. The cover 16 is preferably connected to the main body 15 with screws 13A. The adjacent engagement members 13 have an adjustable connection with each other through the use of connecting rods 17. The connecting rods 17 are loosely engaged in substantially parallel grooves 18a in the main bodies 15. Both ends of the connecting rods 17 are bent to form hooks and thus the distance the rods 17 can move is limited as the rods 17 are stopped from moving within the grooves 18a when the bent hook portion of the rod 17 abuts the end of the groove 18a. Each of the main bodies 15 has an engaging recess or socket 19 by which the engagement member 13 is connected to the end covers 14. In one embodiment, the adjacent end covers 14 are preferably shaped in a Z-like form with offset plate-like parts. The end covers 14 are formed to be thinner at the part that overlaps the adjacent end cover as can be seen in Figure 5. A free end portion of the Z-like form overlaps with a base portion of the Z-like form of the adjacent end cover. The adjacent end covers may abut with each other such that the guards define a smooth outer surface when the rigid strips are in their position of closest approach. The ends of the rigid strips of the bed base structure may be engaged by the engagement members of the guards and the respective adjacent end covers are adjustable so they can move but remain overlapped with each other at their ends when the bed base structure is adjusted. Thus, when guards are used, the ends of the rigid strips 9 and the flexible strips 10 are always covered. As a result of this accidental entrapment of fingers or the like is prevented. Moreover, it is preferable that the engagement members of the guard rails are mutually connected and so joined as to be able to follow the bending motion of the flexible strips and to prevent the bendable portion from becoming uneven due to the weight of the strips themselves or of the patent on the rigid strips. Thus the bendable portion can be bent while maintaining controlled curve. Since the bendable portion can be bent to a smooth and gentle curve, it does not happen that the space at the bent portion is narrowed excessively or sharply to form a displeasing folding pressure at the waist and the abdomen of the patient or the waist and legs of the patient. Furthermore, a result of the present invention is that the patient is shifted less as the parts of the bed base structure are lifted and lowered upon adjustment of the bed. In the specific embodiment illustrated in Figure 1 the bed 1 has a bed base structure generally indicated 2 with a back-support or backrest portion 24 which can be inclined at an adjustable angle with respect to a central or hip-support portion with the adjustment being effected by an electric actuator 3 provided below the bed base 2. The actuator 3 is provided with backrest lifting arms 4 for lifting the backrest portion 25. A leg support portion 26 of the back base 2 is pivotally connected to the central portion 25 by a pivot 27 and includes a bendable portion 8= which allows the height of the patient's knees to be adjusted. Adjustment can be effected by leg-raising arms 5 of the electric actuator 3. The backrest lifting arm 4 contacts the backrest 25 on the under side thereof at a rigid portion joined to the central portion 25 by a flexible or bendable portion 8. A roller 6 ensures smooth operation. Likewise the leg-raising arms 5 have a roller 7 contacting the underside of the bendable portion 8. Each of the bendable portions 8, 8' comprise a plurality of parallel rigid strips 9 and longitudinally expandable parallel flexible strips 10 located between adjacent rigid strips 9 (see Figures 2, 3 and 4). Optionally, the bed base structure may include a hinge if the material comprising the bottom structure is too rigid or this otherwise improves the function of the bed. The rigid strips 9 are preferably extrusion-moulded hollow strips made of a synthetic resin and may be formed to be integral with the flexible strips (see Figures 3 and 4). Further, the flexible strips 10 may also be formed as reinforced bendable sheets 11 connecting the respective adjacent rigid strips 9 on the side to form the inside curve of the bed base 2 (see Figure 3). The bendable sheets 11 are formed to be thinner at their central portions 21 and at the portions 20 intended to be connected with the rigid strips 9 than at the other portions of the bendable sheets 11 so that the bendable sheets 11 can be bent inside at the respective central portions 21 (see Figure 8). The bendable portion 8 can also have a structure in which the rigid strips 9 and the flexible strips 10 are moulded separately and are then connected together (see Figure 2). The ends of the rigid strips 9 of the bendable portion 8 are engaged with the engagement members 13 of guard rails 12 made up from separable units each comprising an engagement member 13 with an end cover 14 attached (see Figures 2 and 4). The rigid strips 9 are preferably secured to the engagement members 13 using a screw 13a. In embodiments where extra support is preferable, the engagement members are interconnected by connecting rods 17. In one example each engagement member 13 has a cover 16 screwed to a main body 15 (see Figure 5). Adjacent engagement members 13 are linked but can be moved with respect to one another through the use of the connecting rods 17. The connecting rods 17 have bent ends loosely engaged in grooves 18a and 18b extending along two substantially parallel lines in each main body 15. The bent ends limit the distance moved by the rods 17 in the grooves 18a and 18b. Each of the main bodies 15 has an engagement socket portion 19 to be engaged with each of the end covers 14. The end covers 14 are preferably formed to be thinner at the portion which overlaps the adjacent end cover 14, so that the respective adjacent end covers 14 may be flush with each other to make the guard rails flat on the outer faces. In the bed 1 shown in Figure 1 having the above-described bed base, if the bed base structure 2 is bent by starting the actuator 3, the bendable sheets 11 or the flexible strips 10 located between the respective adjacent rigid strips are gradually compressed into a V-shape in the bendable portion 8. The flexible strips 10 are compressed and gradually narrow the spaces between the respective adjacent rigid strips 9. As a result, the bendable portion 8 forms a smooth and gentle curve on the side of the bendable sheets 11 connecting the respectively adjacent rigid strips 9 (see Figure 3). If the bendable portion also has guard members these are located at the ends of the rigid strips 9 and flexible strips 10 along the length of the bed. The rigid strips are engaged with the engagement members 13 of the guard rails 12 at the ends of the strips (see Figures 2, 6 and 7). The connecting rods 17 move loosely in the grooves 18a and 18b of the main bodies 15 of the engagement members 13 of the guard rails 12. The respective adjacent engagement members 13 of the guard members 12 can thus move apart from each other as the bed is lifted upwards and the flexible strips 10 are stretched apart. As a result, the end covers 14 are displaced at the mutually overlapped portions. Even if the end covers 14 are moved until both the bent hook ends of the connecting rods 17 are brought into contact with the ends of the grooves 18a and 18b of the main bodies 15, the end covers 14 remain overlapped with each other. The rigid strips 9 and the flexible strips 10 are thus always kept covered by the guard rails 12, to prevent entrapment of fingers by accident (see Figure 7). Furthermore, as described before, since the engagement members 13 of the guard rails 12 are linked to each other in such a manner that they can be adjustably relocated to follow the motion of the flexible strips 10 until both bent ends of the connecting rods 17 are brought into contact with the ends of the grooves 18a and 18b of the main bodies 15, the bendable portion 8 is prevented from dropping due to the weight of (or on) the rigid strips 9 and can be bent to maintain a controlled smooth curve (see Figure 1). Since the bendable portion 8 can be bent to form smooth and gentle curve as described above, it does not result in a space being formed at the bent portion which is excessively narrowed which would cause displeasing folding pressure to the patient, and as a result the patient is relieved of pressure on his waist or abdomen and keeps his body from shifting less. As described above, since the bendable portion 8 has a simple structure in which the flexible strips 10 connect the respectively adjacent rigid strips 9 preferably with bendable sheets 1, to form a comfortable curve, the bed base can be easily produced at low cost. In another embodiment of the present invention the bendable portion 8 is comprised of parallel rigid strips 9 and flexible strips 10 having joints 20 which connect the flexible strips 10 and rigid strips 9, central bendable portions 21 and other connecting portions 22. The joints 20 and central bendable portions 21 are thinner than the other portions 22 and made of a softer more resilient material (see Figure 8a and 8b). Furthermore if the rigid strips 9 and the flexible strips 10 are formed separately and then connected, any individual broken strip can be easily exchanged and thus avoid waste (see Figure 2). As described above, the present invention presents the following advantages: 1) Since the bendable portion can be bent to the desired curvature at an appropriate bendable section of the bed base, the base does not cause any displeasing feelings of pressure to a patient when the bed is bent. 2) The bendable bottom component has a simple structure comprised of flexible strips connecting respectively adjacent rigid strips in which the flexible strips can be formed to be V shaped on the side which forms the inside curve of the bent bendable bottom component. As a result, it can be easily produced at a low cost. 3) Since the flexible strips 10 and rigid strips 9 can be moulded separately and detachably connected, any broken strip can be easily replaced and the bottom component can be maintained at a low cost. 4) The ends of the rigid strips of the bendable portion can be engaged with the engagement members of guard units, the end covers of which are adjustably located and overlapping. The ends of the rigid strips and the flexible strips are therefore always covered and a bed base with such a guard rail keeps fingers and other things away from being caught by accident. 5) The engagement members of the guard rails are mutually connected and controlled to be able to follow the bending motion of the flexible strips and prevent the bendable portion of the bed base from dropping due to the weight of or on the rigid strips. Thus, the bendable portion can be bent to maintain a controlled curve.

Claims: A bed base structure (2) for an adjustable bed (1), including a bendable portion (8, 8=) comprising a plurality of interconnected, substantially rigid, transverse support strips (9), characterised in that the rigid support strips (9) are interconnected by flexible connector strips (10) fixed to, or formed integrally with, adjacent said support strips so as to extend therebetween and interconnect them, the connector strips being so formed as to be deformable to a v-shape in cross-section when compressed by relative movement of the adjacent rigid strips to allow the said bed portion (8, 8=) to adopt a curved configuration. A bed base structure (2) according to Claim 1, characterised in that the bendable portion (8) is located between a first portion (24) of the bed base structure, intended to support a user's back, and a central portion (25) of the bed base structure. A bed base structure according to Claim 1, characterised in that said bendable portion (8=) is located in a position corresponding to that of a user's knees in use of the bed. A bed base structure according to any of Claims 1 to 3, characterised in that guards (12) are provided to cover respective ends of the rigid support strips forming the said bendable portion, the said guards (12) having engagement members (13) engageable with the ends of the rigid support strips and mutually overlapping cover elements (14). A bed base structure according to any of Claims 1 to 4, characterised in that the rigid support strips (9) of the said bendable portion are hollow strips made of a synthetic resin. A bed base structure according to any preceding claim, characterised in that the flexible strips (10) are thinner at a central portion (21) intermediate their edges and at a portion (20) at or adjacent each edge connected to the rigid support strips than at the other parts thereof. A bed base structure according to any preceding claim, characterised in that the said flexible strips of the said bendable portion are less rigid at a central portion (21) intermediate their edges and at a portion (20) at or adjacent each edge connected to the rigid support strips than at the remaining parts thereof. A bed base structure according to Claim 4, or any of Claims 5 to 7 when dependent thereon, characterised in that the said guards (12) comprise a plurality of engagement members (13) engaged with respective ends of the rigid support strips (9) and a plurality of cover members (14), each engagement member (13) having a main body (15) and adjacent engagement members being interconnected by connecting rods (17) which have transversely projecting end portions slotably engaged in substantially parallel grooves (18a, 18b) in the main bodies (15) and acting to limit the relative movement of the linked engagement members, the cover members (14) being so shaped as to provide guard surfaces substantially flush with one another. A bed base structure (2) for an adjustable bed (1), including a bendable portion (8, 8=) comprising a plurality of interconnected substantially rigid, transverse support strips (9), characterised in that the rigid support strips (9) are interconnected by flexible connector strips (10) fixed to, or formed integrally with, opposing faces of adjacent said support strips so as to extend between and interconnect them, the connector strips (10) being so shaped as to allow relative approach and separation of adjacent said rigid support strips to allow the said bed portion to adopt a curved configuration. A bed base structure according to Claim 9, characterised in that each of its said rigid support strips is formed as a separate unit of extrusion-moulded hollow strip made of a synthetic plastics material. A bed base structure according to Claim 9, characterised in that each said flexible strip is a separate unit made of extrusion-moulded synthetic plastics material. A bed base structure (2) for an adjustable bed (1), including a bendable portion (8, 8=), comprising a plurality of interconnected, transverse, substantially rigid support strips (9), characterised in that it further includes a guard structure provided longitudinally along a bendable portion of the bed base structure, the guard structure (12) having a plurality of separate and adjacent guard units each having engagement means (13) engageable with an end of a respective rigid support strip (9) whereby the said guard units can move relative to each other on bending of the bendable base portion. A bed base structure according to Claim 12, characterised in that each guard unit includes a cover (16) and a main body (15) which is engaged with said cover (16) and has at least two substantially parallel grooves (18a, 18b) formed therein, and wherein connecting rods (17) are movable within the said grooves, stop means being provided for limiting the distance each rod can move within a respective groove. A bed base structure according to Claim 13, characterised in that the said grooves (18a, 18b) extend less than the entire width of the guard element main body (15) and the connecting rods (17) have bent ends inserted in respective grooves of adjacent guard elements. A bed base structure according to Claim 14, characterised in that the main bodies (15) of the guard units have end covers (14) attached thereto and shaped such that, when the said guard units are moved to a position of closest approach, the covers have respective surfaces substantially flush with each other to define a substantially continuous guard surface. A bed base structure according to any of Claims 9 to 14, characterised in that the said guard units are engaged with the ends of respective rigid strips and extend across the ends of the interconnecting flexible strips.

Inventors: NOMURA KATSUYOSHI, NOMURA, KATSUYOSHI
Applicants: PARAMOUNT BED KK, PARAMOUNT BED COMPANY LIMITED
Application year: 1994
Main classification: A47C23
IPC codes: A47C20, A47C23